One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,10)(8,11)(9,12)(14,19)(15,23)(17,25)(20,21)(22,28)(24,27) involution — undirected(5,7)(6,9)(8,12)(10,11)(13,14,17,19,18,22,25,28)(15,24,26,21,23,20,16,27)(2,4)(7,12)(9,10)(13,15)(14,20)(16,25)(17,26)(18,23)(19,27)(21,28)(22,24) involution — undirected(5,7)(6,10)(8,12)(9,11)(13,16,18,26)(14,21,22,27)(15,25,23,17)(19,20,28,24)(7,12)(9,10)(15,23)(16,26)(20,24)(21,27) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.